EmonPi

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Revision as of 16:18, 3 April 2015 by Glyn (Talk | contribs) (Port Map)

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Raspberry Pi Energy Monitoring Shield

Hardware Technical Wiki Documentation - IN DEVELOPMENT!

Technical Features

  • 2 x CT Current Sensor Inputs - designed for 100A max YHDC clip-on SCT-013-000
  • 1 x AC Voltage Input - designed for 9V AC power adapter
  • Arduino compatible ATmega328P - sketch upload direct from the Pi via GPIO serial
  • RJ45 connector for connecting DS18B20 temperature sensors, IRQ pulse counting sensor, and access to power and spare I/O including analog and PWM
  • RFM69CW 433Mhz RF Radio
  • I2C LCD (16 x 2) with control push button
  • Raspberry Pi Shutdown Button

Overview Diagram

EmonPi V1.4 Diagram.jpg

Port Map

EmonPi GPIO.png

emonPi ATmega328

Arduino Pin AVR Special Function emonPi V1.6 Atmega 328 Raspberry Pi
Analog 0 (D14) AC Voltage
Analog 1 (D15) CT1
Analog 2 (D16) CT2
Analog 3 (D17)
Analog 4 (D18) (SDA)
Analog 5 (D19) (SCL)
Analog 6 (D20) RJ45 pin 8 – ADC6 / Dig20
Analog 7 (D21)
Digital 0 (RXD) FTDI Tx GPIO 14 / pin 8
Digital 1 (TXD) FTDI Rx GPIO 15 / pin 10
Digital 2 (int0) PWM RFM12B/69CW INT / (JP5 – RJ45 pin 7)
Digital 3 (int1) PWM RJ45 pin 6 – Pulse counter
Digital 4 RJ45 pin 4 – one-wire DS18B20
Digital 5 PWM Raspi GPIO 17 / Pin 11 GPIO 17 / Pin 11
Digital 6 PWM OOK Tx
Digital 7
Digital 8 Shutdown PTM Button
Digital 9 PWM emonPi PCB LED
Digital 10 (SS) PWM RFM69CW SEL
Digital 11 (MOSI) PWM RFM69CW SDI
Digital 12 (MISO) RFM69CW SDO
Digital 13 (SCK) RFM69CW SCK

Raspberry Pi GPIO

Raspberry Pi GPIO RasPi Function emonPi V1.6 ATmega328
2 (0 REV1) I2C SDA I2C LCD
3 (1 REV 1) I2C SCL I2C LCD
4 (pin 7) ATmega328 reset
7 SPI CS
8 SPI CS
9 SPI
10 SPI
11 SPI
14 UART Tx Dig 0 /Rx
15 UART Rx Dig 1 / Tx
17 (pin 11) Atmega Dig 5 – shutdown signal
18
22
23 (pin 16) LCD push button
24
25
27 (21 REV 1)

All unused Raspberry Pi ports can be used to connect additional peripherals, make sure to take account of additional current requirements.

Raspberry Pi Compatibility

The emonPi has been designed to with the Raspberry Pi Model B+ and Pi2.

The emonPi will also work on the Model-B, although due to physical differences it won't fit inside the emonPi aluminium case. The use the emonPi on the Model B a 13-pin GPIO extender is needed instead of the 20-pin extender included; please leave a note at checkout when ordering.


Power Supply

The emonPi is powered by 5V DC via a mini-B-USB socket. The Raspberry Pi is powered by the emonPi via the GPIO pins. The emonPi board itself runs at 3.3V provided by on on-board voltage regulator. The Raspberry Pi's 3.3V rail is left un-touched by the emonPi.

We recommend at least a 1.2A 5V USB power supply

SD Card Image

Based on Raspbien

Download

Build

Run emonPi install script. See script for details

$ git clone https://github.com/openenergymonitor/emonpi.git $ cd emonpi $ sudo ./install

Uploading Arduino Firmware

.hex file can be uploaded:

$ avrdude -v -c arduino -p ATMEGA328P -P /dev/ttyAMA0 -b 115200 -U flash:w:sketch_name.hex

For further info see avrdude-rpi readme

Connectivity

RFM69CW

OOK

RJ45 Socket

This is not an Ethernet socket! Do not plug into an Ethernet router, this will cause the emonPi power rail to be shorted. This will be fixed in next rev of emonPi. As a precaution the emonPi V1.5 will be shipped with a protector cap on this RJ45 socket.


The emonPi RJ45 socket can be used to connect multiple DS18B20 temperature sensors, an optical pulse counting sensor or access power rails and aux I/O/


The RJ45 uses standard pinout used by other manufacturers of DS18B20 temperate sensing hardware such as Sheep Walker Electronics


RJ45 Pinout


DS18B20 Temperature

A DS18B20 digital temperature sensors can easily be connected by the emonPi by connecting the sensors into the emonPi's RJ45 connector. The default firmware (discrete sampling) supports auto-detecting and reading from of up to six DS18B20 sensors.


RJ45 Pinout


DS18B20 sensor on RJ45


RJ45 to Terminal Block Breakout

Encapsulated DS18B20 temperature sensor


Further RJ45 breakouts are available from Sheep Walk Electronics


Pulse Counting

Many meters have pulse outputs, including electricity meters (single phase, 3-phase, import and export), gas meters, water flow meters etc. The pulse output may be a flashing LED or a switching relay (usually solid state) or both. We recommend using the optical interface where available as this decouples the monitoring equipment from any high/mains voltages.


In the case of an electricity meter, a pulse output corresponds to a certain amount of energy passing through the meter (kWh/Wh). For single-phase domestic electricity meters (eg. Elster A100c) each pulse usually corresponds to 1 Wh (1000 pulses per kWh). For water and gas meters they will usually be marked to show the quantity of water (litres/gallons) or of gas (cubic meters/cubic feet) that each pulse represents.


The standard emonPi has one spare interrupt input (IRQ 1, Dig3) which can be used for pulse counting. This is accessible on the RJ45 socket


The second interrupt IRQ0 is usually used by the RFM69CW module on the emonPi. If the RF module is not present this interrupt can be jumped on the PCB (JP5) to be accessible on RJ45, see below for pin out:


RJ45 TSL257


TSL257 emonPi


Aux I/O

Unused input / output ADC 6 / Digital 20 is available on RJ45 connector for general purpose.

Electrical Characteristics

Electrical Characteristics

emonPi Datasheet
Function Parameter Min Recommended

Max / typical

Absolute Max


Notes
CT 1-2 Monitoring Power @ 240V 23kW 60kW Using 22R burden and YHDC SCT-013-00 with 22 turns
3.3V Rail current output When powering with 5V USB 150mA 168mA Limitation SOT22 MCP1700 Ta=40C Vi=5.25V
5V Input Voltage USB +3.4V +6V +6.5V (see note 1) See note 1
3.3V Supply Voltage on 3.3V supply rail 2.6V * 3.3V 3.9V * *ADC readings will be incorrect if Vcc!=3.3V
Power Consumption with Raspberry Pi 2 @3.3V 7mA no RasPi - 14mA RasPi Halted 300mA RasPi idle 500mA+ RasPi Load With ATmega328, RFM69CW, Edimax WIFI + RasPi2

Open-Hardware Design Files

See emonPi hardware GitHub repo

EmonP V1.5 brd track blacks.png

Open Development

The emonPi has been developed with input from the OpenEnergyMonitor community. See origional development OpenEnergyMonitor.org forum thread.

[emonPi Development Photos Album

Physical Dimensions

PCB: 99.2mm x 76.1mm Enclosure: 99mm x 85mm x 50mm

License

The emonPi is part of the OpenEnergyMonitor.org project

The hardware designs (schematics and CAD files) are licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

The firmware is released under the GNU GPL V3 license

The documentation is subject to GNU Free Documentation License

The hardware designs follow the terms of the OSHW (Open-source hardware) Statement of Principles 1.0

Media

emonPi Stock Photos

Development Photos

Environmental & Life Cycle

Disclaimer

OUR PRODUCTS AND ASSEMBLY KITS MAY BE USED BY EXPERIENCED, SKILLED USERS, AT THEIR OWN RISK. TO THE FULLEST EXTENT PERMISSIBLE BY THE APPLICABLE LAW, WE HEREBY DISCLAIM ANY AND ALL RESPONSIBILITY, RISK, LIABILITY AND DAMAGES ARISING OUT OF DEATH OR PERSONAL INJURY RESULTING FROM ASSEMBLY OR OPERATION OF OUR PRODUCTS.

The OpenEnergyMonitor system is sold as a development kit to empower members of the openenergymonitor community to to get involved with the OpenEnergyMonitor open-source energy monitoring development project.

Your safety is your own responsibility, including proper use of equipment and safety gear, and determining whether you have adequate skill and experience. OpenEnergyMonitor and Megni registered partnership disclaims all responsibility for any resulting damage, injury, or expense. It is your responsibility to make sure that your activities comply with applicable laws, including copyright. Always check the webpage associated with each unit before you get started. There may be important updates or corrections. All use of the instructions, kits, projects and suggestions given both by megni.co.uk, openenergymonitor.org, shop.openenergymonitor.org and wiki.openenergymonitor.org are to be used at your own risk. The technology (hardware , firmware and software) are constantly changing, documentation (including build guide and instructions) may not be complete or correct.

If you feel uncomfortable with assembling or using any part of the kit / unit, please return it to us, we will happy to give a full refund.